Desired foam characteristics for consumer products, such as personal care compositions, are dependent upon the end use and consumer expectations. If a consumer foamed product is expected to be applied to a surface other than the hands of the consumer, there are properties that define acceptable foam characteristics. Acceptable foam characteristics in personal care composition are exemplified by foam that holds its shape and stays in a consistent form in order to transfer from a consumer's hand to the desired location on the consumer's body (e.g., hair, face, arms, legs, etc.). If foam collapses prematurely and becomes a liquid, any movement of the consumer's hand, specifically the palm of the hand, from a horizontal position to a non-horizontal position for application causes the foam to run, drip or otherwise move from the consumer's hand before the foam reaches the desired location and is considered undesirable. This foam characteristic is especially undesirable when working with personal care compositions that can change the color or tint the surface it touches, such as hair dying composition or skin lightening ortinting compositions.
Likewise, foam that is too “airy” cause consumers to apply the personal care composition at a higher frequency as the amount of personal care composition per dosage is diminished with a foam containing more air than composition.
Manually-actuable, non-aerosol dispenser useful herein includes squeeze foamers. The basic mechanism by which such foamers operate is that liquid from a container reservoir is pumped into a liquid/air mixing chamber where air is mixed with liquid held within the container. Foam is generated (air into liquid) and then passed through one or more screens to refine the foam which is then dispensed. Traditionally, liquids that were used in such foamers were described as having a “high” viscosity when the viscosity (at 25° C.) is 100 cps (0.1 pascal seconds) or less. See US 2004/0254253 A1. Although viscosities (at 25° C.) of up to 300 cps (0.3 pascal seconds) of liquids for such foamers has been discussed. See US 2004/0213752 A1. Use of polymers to increase the viscosity of a personal cleaning composition that is foamed is known, but with target viscosities of the composition are targeted to be less than 100 cps (0.1 pascal seconds). See WO 91/14759.
One drawback of the manner under which the manually-actuable, non-aerosol dispenser foamers operate to generate foam is that higher viscosity materials (higher than 300 cps or 0.3 pascal seconds) make squeezing too difficult as large amounts of work (an applied force moving an object in a distance) is required to expel higher viscosity liquids from such foaming containers.
Additional benefits of the present invention include a desired foam specific volume of the resulting foamed personal care composition, reduction in force required to actuate the manually-actuable, non-aerosol dispenser, improved end results of the personal care composition such as improved color results and improved amount of personal care product delivered per dosage. The present disclosure includes foamers that reduce the amount of work required to expel a desired quantity of foam, while substantially preserving the desired foam specific volume, thereby improving the ease of dispensing foam personal care compositions.